HIT (Heterojunction with Intrinsic Thin layer) Solar Cells

HIT solar cell has become the subject of intense research within the photovoltaic research community, due to its low process temperature in comparison with crystalline silicon (c-Si) solar cell and comparatively high efficiency (η). This solar cell structure uses thin intrinsic amorphous silicon layers as a surface passivator and also as a buffer layer at the top and bottom surfaces of n-type crystalline silicon (c-Si) wafer. A highly doped n+-type bottom layer acts as a back surface field, while a thin p-type a-Si top layer is used as an emitter. Sanyo Electric Company, a Japan-based company and part of Panasonic, invented the crystalline silicon wafer–based hetero-junction solar cell concept.

Key Features

The key features of the Panasonic HIT™ are as follows:

• High temperature stability
• High efficiency, roughly 27% more power when compared to 260 W competitor panels
• Maximum use of available roof space
• Generates higher power for the same system size
• More power per area
• RoHS complaint
• PID resistant

In order to decrease the area occupied by the solar cells, on has to increase their efficiency. One solution is increasing the single crystal solar cells by surface passivation and increasing the minority carrier lifetime in the bulk. Efficiency as high as 24 percent have been achieved.

There is also the multijunction solar cells which may be based on single crystalline silicon and amorphous silicon. Or on multijunction compound semiconductors. Efficiency as high as 37 percent has been achieved.

There is also the new materials specially the pervoskite solar cells which showed an efficiency up to 20 percent but they are still under development because of long term stability problems. Such material can be used to build also multijunction solar cells as the active material is very thin.

The Multijunction based on the 3-5 compounds can be operated at high temperatures and thereby they can be operated at concentrated sun radiation.

Best wishes

Dear Pisipaty Srinivas Kishore

Researchers have longed looked for ways to improve the efficiency and cost-effectiveness of solar cells - the life blood of solar PV systems. A solar PV array is comprised of hundreds, sometimes thousands of solar cells, that individually convert radiant sun light into electrical currents. The average solar cell is approximately 15% efficient, which means nearly 85% of the sunlight that hits them does not get converted into electricity. As such, scientists have constantly been experimenting with new technologies to boost this light capture and conversion.

Light-Sensitive Nanoparticles. Recently, a group of scientists at the University of Toronto unveiled a new type of light-sensitive nanoparticle called colloidal quantum dots, that many believe will offer a less expensive and more flexible material for solar cells. Specifically, the new materials use n-type and p-type semiconductors - but ones that can actually function outdoors. This is a unique discovery since previous designs weren't capable of functioning outdoors and therefore not practical applications for the solar market. University of Toronto researchers discovered that n-type materials bind to oxygen - the new colloidal quantum dots don't bind to air and therefore can maintain their stability outside. This helps increase radiant light absorption. Panels using this new technology were found to be up to eight percent more efficient at converting sunlight.

Gallium Arsenide. Researchers at Imperial College University in London believe they have discovered a new material - gallium arsenide - that could make solar PV systems nearly three times more efficient than existing products on the market. The solar cells are called "triple junction cells" and they're much more efficient, because they can be chemically altered in a manner that optimizes sunlight capture. The model uses a sensor-driven window blind that can track sun light along with "light-pipes" that guide the light into the system.

Regards

Thank you Thulasi Ram, Abdelhalim Zekry and Omar Hazem Mohammed for providing answers about recent development in solar cells. The contents are worth noting. Can I have some more information regarding?

Poster Hotspots of Solar Potential in India

Presently solar panels have efficiency ratings as high as 22.2%, whereas the majority of panels range from 15% to 17% efficiency rating. Sun Power panels are known for being the most efficient solar panel brand available in these days. Most solar panel are used recently such as: Thin-Film: Amorphous Silicon Solar Panels (A-SI) ~7-10%,Polycrystalline Solar Panels (p-Si) ~15%, Monocrystalline Solar Panels (Mono-SI) ~20%, Concentrated PV Cell (CVP) ~41%

Thank you Bharath Setturu and Sham Singh for providing useful answers.

Now a days solar cells are mostly and encouraged to be used in country like India. India has a greater potential for extraction of solar energy due to climatic and environment conditions. Experiments are going on to use semi conductors and advance materials as solar cells.

Use of Solar cells are increasing day by day in both government and private sectors since it is clean source of energy. Now a days, research is going on to improve the solar cell design, usually semi conductors are used in research and a limitation is small size in array.

Solar cells are now being used regular in public and private sectors for different purposes and is a clean source of energy. Semi conductor materials are now being used to reduce the size of the cell array and improve efficiency.

Follow answer

Solar cells are getting importance now a days as this has been proved as clean source of energy. Solar cells previously are photovoltaic and currently semiconductor materials are coming. This reduces the size of panel for a stipulated power output.

Use of photovoltaic cells for solar power generation are now replaced by semiconductor materials which is having a limited shape and size for the same power generation. Now a days they are used in space applications.

Solar energy is becoming reliable with almost no pollution. Several ways are taken into consideration to reduce the panel size of solar cells so that maximum power output can be obtained. Owing to this, I think that semi conductors are the promising source.

As solar energy is known to be the clean source of energy, generation of solar power can be by solar cells. Solar cells previously are big. Now a days, the materials for solar cells are developed in such a way that these are made handy, small and develop or produce power in an easy way.

Solar cells are generally photovoltaic cells which are used for power generation. Recent advancements like semiconductors are used which becomes small, compact and gives a greater power output.

Solar cells are now in increase demand for all. This is being used in house hold, for street lights and in space also. Photovoltaic cells are used previously but now, semi conductors like germanium etc. are used in manufacture to get compactness and generate high power for same area taken into consideration.

Recent advancements in generating of power is being investigated and in this direction, semi conductors using germanium etc. could look a way for compactness and generating more power.

Use of solar cells are becoming important due to clean source of energy and plenty available to harness. Previously one used photovoltaic cells and now they are currently replaced by semiconductor materials like germanium etc and recently this has gone application to space.

Solar cells now being adopted in all organizations in order to have clean power generation and combining with other source of power for giving effective power generation. Solar cells now a days going in advance using semiconductor materials instead of photovoltaic cells which are becoming promising source of energy.